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Should all new cars have electronic speed limiters?
Miscellaneous UK car topics Other UK car topics (uk.rec.cars.misc)
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#121
 
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Re: Should all new cars have electronic speed limiters? -
05-14-2007
, 01:30 AM
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John Beardmore (wookie (AT) wookie (DOT) demon.co.uk) gurgled happily, sounding much like they were saying : Your wording "It was caused solely by..." suggests that you've totally missed the point. No, it suggests I've actually watched the video. Everybody would have been fine if the fuckwit hadn't tried to swerve to miss the animal. |
#122
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Your wording "It was caused solely by..." suggests that you've totally missed the point. No, it suggests I've actually watched the video. Everybody would have been fine if the fuckwit hadn't tried to swerve to miss the animal. The animal wouldn't have been fine!! |
#123
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Hmmm... Going up hill is when the biggest proportion of the mechanical output of the engine is doing necessary work. Within reason it's hard to see the problem here. And in fact fuel efficiency courses tell you to maintain the speed if |
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whilst enjoying a higher speed "for free" downhill. But it's not 'for free'. If you speed up, you'll probably just 'do more work [a higher proportion of the engines mechanical work] on the atmosphere'. Better to cut the engine, coast down, and loose a minimum of engine power to the atmosphere. What benefit is there of cutting off the engine? |
--
Conor
Light travels faster than sound. This is why some people appear bright
until you hear them speak.........
#124
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In article <EwSouKY+70RGFwJE (AT) wookie (DOT) demon.co.uk>, John Beardmore says... Hmmm... Going up hill is when the biggest proportion of the mechanical output of the engine is doing necessary work. Within reason it's hard to see the problem here. And in fact fuel efficiency courses tell you to maintain the speed if possible up hill. Yes within reason. In actual fact you'll see the driver-controlled cars |
cruise-controlled ones will react much faster to the deceleration and open the
throttle earlier.
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whilst enjoying a higher speed "for free" downhill. But it's not 'for free'. If you speed up, you'll probably just 'do more work [a higher proportion of the engines mechanical work] on the atmosphere'. Better to cut the engine, coast down, and loose a minimum of engine power to the atmosphere. What benefit is there of cutting off the engine? |
gravity to provide its maximum effect.
#125
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In sci.environment, John Beardmore wookie (AT) wookie (DOT) demon.co.uk wrote The transponders would also be hooked to law enforcement officials and weather systems. Backup monitors would also be hooked to the former, so that a cruiser can be dispatched to deal with the offending automobile, which obviously doesn't have a working limiter under certain observation patterns. I think most drivers would feel this to be excessive micro-management. Aye. But then, many drivers apparently feel the 65 mph speedlimit to also be excessive micro-management. |
risks might be acceptable.
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Electric cars are not the most efficient. That might go to a Stirling engine. I'm not convinced unless so have some very good on board use for low grade heat ? Best use I have for it is one's tootsies in the passenger compartment, and I'm not sure how "low grade" one is discussing here. |
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Most likely the heat will simply be rejected to the car following. :-) |
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What give you the idea these would be efficient in an automotive context ? I'll have to get back to you on that; mind you, I was under the apprehension that they were more efficient than the current reciprocating piston affair. |
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I'm hoping for a continously variable transmission at some point, which would eliminate the need for batteries in a post-hybrid car. Hmmm... Sounds more like the variable speed drive systems that are probably already in hybrid cars. The idea is probably vaguely similar, though I was under the understanding that many hybrid cars use electric drive. Electric motors need no tranny. :-) |
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People are more likely to be persuaded to go carbon neutral by education than by force. There are some problems with education, as it's based on trust. There are also a lot of problems with institutional mistrust. How do we know they're not trying something? For all we know it's a gigantic conspiracy for those in the environmental movement to deny everyone their rightful dollop of fuel, as opposed to any concern regarding increased average global temperatures, weather instability, food losses, etc. Maybe you should learn some environmental science then ? Maybe. :-) Personally, I think AGW is a problem, but don't know precisely what we can do about it. (Never mind whether it's human-caused. |
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It's happening. Can we cool the Earth back to a comfortable level?) |
damage, but that still strikes me as a necessary start.
Cheers, J/.
--
John Beardmore
#126
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John Beardmore wrote: whilst enjoying a higher speed "for free" downhill. But it's not 'for free'. If you speed up, you'll probably just 'do more work [a higher proportion of the engines mechanical work] on the atmosphere'. Better to cut the engine, coast down, and loose a minimum of engine power to the atmosphere. Modern cars don't work like that. Going downhill and speeding up will allow the engine to overrun, which will cut the fuel to *zero*. |
the engine would be taking energy from the forward motion.
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If you are driving well manually, you can allow that spped to be kept for the next incline with very light throttle, |
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whereas the cruise will let the stored energy bleed off and then have to work harder to get up the next hill. |
it is the case, is down to hitting the hill in a part of the power band
where it's easy to get power.
I'm not sure that this will make it the least fuel option even if it
feels like less 'effort'.
I still suspect that 'burn and coast' may offer better economy.
Cheers, J/.
--
John Beardmore
#127
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In article <EwSouKY+70RGFwJE (AT) wookie (DOT) demon.co.uk>, John Beardmore says... Hmmm... Going up hill is when the biggest proportion of the mechanical output of the engine is doing necessary work. Within reason it's hard to see the problem here. And in fact fuel efficiency courses tell you to maintain the speed if possible up hill. |
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whilst enjoying a higher speed "for free" downhill. But it's not 'for free'. If you speed up, you'll probably just 'do more work [a higher proportion of the engines mechanical work] on the atmosphere'. Better to cut the engine, coast down, and loose a minimum of engine power to the atmosphere. What benefit is there of cutting off the engine? |
friction.
Not sure what the downsides might be for the engine. Maybe lower rate
of cooling ?
Beyond the engine, loss of power steering and loss of vacuum for brakes
are the obvious issues.
Cheers, J/.
--
John Beardmore
#128
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In message <48ckh4-gpi.ln1 (AT) sirius (DOT) tg00suus7038.net>, The Ghost In The Machine <ewill (AT) sirius (DOT) tg00suus7038.net> writes I'm hoping for a continously variable transmission at some point, which would eliminate the need for batteries in a post-hybrid car. Hmmm... Sounds more like the variable speed drive systems that are probably already in hybrid cars. The idea is probably vaguely similar, though I was under the understanding that many hybrid cars use electric drive. Electric motors need no tranny. :-) I don't think they are 1:1 to the hubs ? |
sturdy and reliable) planetary gearbox with the petrol and electric drive
motor attached to one side and the roadwheels at the other. Varying the revs
on the drive motor and the i.c motor separately gives a widely varying
continuous ratio at the road.
Using the road+i.c. to drive the electric motor gives you regenerative
braking/charging.
Using the drive motor to start the i.c. engine gives you a *very* fast
startup spin which reduces both emissions and the chance of a failed start
just when you need it.
There's a good online simulation of how it all works here
<http://homepage.mac.com/inachan/prius/planet_e.html>
#129
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Conor wrote: In article <EwSouKY+70RGFwJE (AT) wookie (DOT) demon.co.uk>, John Beardmore says... Hmmm... Going up hill is when the biggest proportion of the mechanical output of the engine is doing necessary work. Within reason it's hard to see the problem here. And in fact fuel efficiency courses tell you to maintain the speed if possible up hill. Yes within reason. In actual fact you'll see the driver-controlled cars decelerate slightly at least at the start of an incline, whereas the cruise-controlled ones will react much faster to the deceleration and open the throttle earlier. |
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whilst enjoying a higher speed "for free" downhill. But it's not 'for free'. If you speed up, you'll probably just 'do more work [a higher proportion of the engines mechanical work] on the atmosphere'. Better to cut the engine, coast down, and loose a minimum of engine power to the atmosphere. What benefit is there of cutting off the engine? Now coasting is really not recommended, |
Well deprecated !Quote:
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but it does allow the action of gravity to provide its maximum effect. |
Or at least the maximum proportion of the acceleration.Cheers, J/.
--
John Beardmore
#130
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In message <XfL1i.18616$Ro3.7127 (AT) text (DOT) news.blueyonder.co.uk>, PC Paul urd (AT) bitrot (DOT) co.uk> writes John Beardmore wrote: whilst enjoying a higher speed "for free" downhill. But it's not 'for free'. If you speed up, you'll probably just 'do more work [a higher proportion of the engines mechanical work] on the atmosphere'. Better to cut the engine, coast down, and loose a minimum of engine power to the atmosphere. Modern cars don't work like that. Going downhill and speeding up will allow the engine to overrun, which will cut the fuel to *zero*. I would have thought that when the fuel consumed was zero, friction in the engine would be taking energy from the forward motion. If you are driving well manually, you can allow that spped to be kept for the next incline with very light throttle, But some then... whereas the cruise will let the stored energy bleed off and then have to work harder to get up the next hill. There my be some perception to this effect, but I suspect that this, if it is the case, is down to hitting the hill in a part of the power band where it's easy to get power. I'm not sure that this will make it the least fuel option even if it feels like less 'effort'. I still suspect that 'burn and coast' may offer better economy. |
But 'keep rigidly within a few mph regardless' is very unlikely to offer
anything like the best economy. Which is where we started...
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